A stapler is a device that binds sheets of paper by driving a staple.
The first stapler was made by use of a principle of a machine gun in the 19th century in Connecticut, United States.
Staples used for the stapler are usually made of iron or steel. Alternatively, the staple may be made of copper and various staples, such as colored ones, are commercially available recently.
A process of fabricating the staple is as follows. First, an iron wire is electroplated for the purpose of corrosion proof and the iron wire is then extracted and cut to have a certain size and shape. The iron wires are adhered to each other by means of an adhesive material, and then pressed and bent to form a long strip of staple.
After such a stapler was invented and supplied in the early 1900s, the stapler was used to bind relatively thin books or papers. The bookbinding using the stapler is widely utilized for magazines or newspapers at present.
In the case of books which are bound by the stapler in homes, offices, schools and libraries, paper is discolored into brown, and is disintegrated into a pile of fragments and dust around the staple. If the symptoms continue or get worse, the holes, through which the legs of the staple pass, become wider, such that the staple no longer plays a role of binding the book. In particular, the symptoms occur in the books published in the early 1900s. Even though the symptoms are different depending upon a keeping method and a degree of corrosion, a discoloring range of the paper is gradually enlarged, or the paper is gradually disintegrated into a pile of fragments and dust around the staple.
Some studies analyzed the causes of the symptoms and researches on the damage of paper caused by iron ions have been conducted. The oxidation of iron ions contained in liquid ink has been studied, which is referred to as iron ink gall. This is caused by the difference between particles of the paper and the staple and the interface between the staple and the paper is discolored into brown. The discolored paper is crushed since a length of the paper is shortened.
Meanwhile, when it is necessary for the staple to be removed, the staple can be removed by a staple remover or by hands. However, since the staple is made of iron or steel, it may not be easy to remove the staple despite using the stapler remover. In addition, in the case of removing the staple by hands, nail may be broken or damaged.